SOLUTION: Determine the equation of the axis of symmetry. y = -5x2 - x + 9 what is the answer to this ? ive tried multiple times and im almost out of timeeeee ?

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons  -> Quadratic Equation Lesson -> SOLUTION: Determine the equation of the axis of symmetry. y = -5x2 - x + 9 what is the answer to this ? ive tried multiple times and im almost out of timeeeee ?      Log On


   

Question 335604: Determine the equation of the axis of symmetry.
y = -5x2 - x + 9
what is the answer to this ? ive tried multiple times and im almost out of timeeeee ?
Found 2 solutions by Alan3354, Fombitz:
Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
Determine the equation of the axis of symmetry.
y = -5x2 - x + 9
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x = -b/2a is the axis of symmetry
x = 1/(-10)
x = -1/10

Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
Convert the equation to vertex form, y=a%28x-h%29%5E2%2Bk where (h,k) is the vertex, by completing the square.
y=-5x%5E2-x%2B9
y=-5%28x%5E2%2B%281%2F5%29x%29%2B9
y=-5%28x%5E2%2B%281%2F5%29x%2B1%2F100%29%2B9%2B5%2F100
y=-5%28x%2B1%2F10%29%5E2%2B181%2F20
The vertex lies on the axis of symmetry.
highlight%28x=-1%2F10%29
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